JP3311278B2 - Edge drop control device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to edge drop system GoSo location of the strip material in the rolling of such cold-rolling mill.

[0002]

2. Description of the Related Art It is known that in strip rolling such as cold rolling, a sharp decrease in the thickness called edge drop occurs at both ends in the width direction of the strip. If the edge drop amount is large, a large amount of trimming is required to secure a desired plate thickness quality. As a result, the yield and the production efficiency have been greatly reduced.

[0003] As a method of improving such edge drop, taper grinding is performed on one end of each of the upper and lower work rolls on the opposite side, and the taper grinding portion is positioned at each end of the material to be rolled. Methods of doing so are widely known. In a typical cold tandem rolling mill, at least a rolling stand having the pair of single trapezoidal work rolls is provided.
It is common practice to install a rolling stand in which one or more stands including a stand are mounted, and a final stand on the exit side, incorporating a work roll having a plain shape.

Japanese Patent Application Laid-Open No. Hei 4-200813 discloses that an edge drop meter is installed on the exit side of a rolling mill, and the edge drop amount detected by the gauge is fed back to a rolling stand having upper and lower trapezoidal work rolls. An edge drop control method by controlling a vertical work roll shift amount is shown.

[0005]

However, in this method, the shift amounts of the upper and lower work rolls are individually controlled based on the measurement results of the edge drop meters at both ends. Therefore, the upper and lower work roll shift positions are asymmetrical, and the distance from the end of the strip material to the tapered shoulder of each work roll is different. This means that in rolling the strip, the left and right sides of the rolling mill are inevitably unbalanced, which may meander or break the strip. This tendency becomes more remarkable as the left and right imbalance is larger.

According to the present invention, in edge drop control,
It is an object of the present invention to control the unbalance between the left and right sides of the rolling mill so as not to be excessive, and to perform stable control in which the meandering or breakage of the strip material is avoided.

[0007]

[0008]

SUMMARY OF THE INVENTION The present invention provides means for axially moving upper and lower work rolls of a rolling mill for rolling a strip, and a work roll shift position detecting means for detecting shift positions of the upper and lower work rolls. Means, edge drop measuring means for measuring the edge shape of each end of the strip, and upper and lower work rolls for calculating the respective shift amounts of the upper and lower work rolls from the respective edge drop amounts measured by the edge drop measuring means. Shift change amount calculating means, shift position difference upper limit value setting means for setting an upper limit value of the shift position difference between the upper and lower work rolls,
A shift position difference is calculated from the shift position of each work roll measured by the work roll shift position detecting means, and the calculated value exceeds an upper limit set by the upper and lower work roll shift position difference upper limit setting means. When there is, the upper and lower work roll shift position difference calculating means for issuing an alarm signal, and the upper and lower work roll shift amount is calculated based on the shift change amount calculated by the upper and lower work roll shift amount calculating means, to control the respective shift positions of the upper and lower work rolls, the alarm signal The object has been solved by an edge drop control device including upper and lower work roll shift position control means having a function of canceling a shift change in a direction in which a shift amount increases when received.

[0009]

FIG. 1 shows the configuration of an edge drop control system in a cold tandem rolling mill. FIG.
Shows only the upper and lower work roll shift rolling stand 12 which is the first stand on the entry side of the cold tandem rolling mill and the control system configuration thereof, and omits all other parts of the line which do not constitute the present invention. . As described above, the upper and lower work rolls 13 and 14 have a shiftable single trapezoidal structure. As shown in FIG. 2, the strip 10 is rolled with its upper and lower portions sandwiched between an upper work roll 13 and a lower work roll 14. The upper work roll 13 and the lower work roll 14 are backed up by the upper backup roll 15 and the lower backup roll 16, respectively, and are independent so that the trapezoidal structure indicated by the arrow in the figure is located at the edge of the strip 10. Have been shifted.

On the exit side of the cold tandem rolling mill (in FIG. 1, the exit side of the upper and lower work roll shift rolling stand 12), an edge drop meter 1 for measuring the edge drop at both ends of the strip 10 is provided at each end. The edge drop signal is fed back to the work roll shift control device 20. Work roll shift controller 20
Controls the shift of the upper and lower work rolls of the upper and lower work roll shift rolling stand 12 based on the feedback signal.

Here, the feedback control is illustrated, but an edge drop meter may be provided on the entry side, and feed-forward may be performed based on the edge drop amount on the entry side to perform predictive control of vertical work roll shift. Further, the setup control for setting up the upper and lower work roll shift amounts based on the results of the edge drop measured offline may be performed without installing the edge drop meter online.

Next, the work roll shift control device 20, which is a main part of the present invention, will be described in detail. The measurement signal of the edge drop meter 1 is transmitted to the work roll shift controller 20.
Is input to the upper / lower work roll shift change amount calculator 2 and the required shift change amounts of the upper and lower work rolls are calculated. Then, the shift change amount is input to the upper and lower work roll shift position control unit 3, and the position control of the upper and lower work rolls is performed based on the change amount. The shift positions of the upper and lower work rolls are measured by the respective work roll shift position detectors 5, and the measured values are taken into the upper and lower work roll shift position difference calculator 6, and the upper and lower work roll shift position differences are calculated. Here, the upper limit value set in the upper / lower work roll shift position difference upper limit value setting unit 4 is also taken into the upper / lower work roll shift position difference calculation unit 6. The calculated upper and lower work roll shift position difference is constantly compared with the set upper limit value, and when the upper limit value is exceeded, an alarm signal is transmitted to the upper and lower work roll shift position control unit 3. The vertical work roll shift position control unit 3 cancels the shift position change in the direction in which the shift amount increases while the alarm signal is being captured, and the shift position is held at that position. On the other hand, shift control in the direction of reducing the shift amount is performed as it is because the shift position difference is in the direction of decreasing. Thus, the control is always performed such that the upper and lower work roll shift position difference does not exceed the upper limit of the work roll shift position difference.

[0013] top and bottom work rolls, with each limit point shift position determined from the mechanism, so that the shift position is controlled therein. On the other hand, the upper and lower work roll shift position difference limit defined based on the present invention, Ru Tei determined appropriately within a range that does not cause operational problems such as operation on meandering.

[0014]

[0015]

[0016] For this reason, beyond the upper limit shift position difference between the upper and lower work rolls is set, does not grow to lead to big problems meandering or breakage of the strip material.

In the above description, the application of the present invention to edge drop control by shift movement of a single trapezoidal work roll has been described. However, the present invention can be similarly implemented when used together with a work roll cloth or a work roll bend. Need not be explained.

[0018]

According EXAMPLES time chart shown in FIG. 3, an embodiment of the control of the present invention. In FIG. 3 , the horizontal axis represents the time axis. FIGS. 3 (a) shows a vertical work roll shift position difference. Similarly, hereinafter, (b) shows the upper work roll feedback control output, (c) shows the upper work roll shift position, (d) shows the lower work roll feedback control output, and ( e ) shows the lower work roll shift position. I have. Here, the line indicated by Δδ in (a) indicates the upper and lower work roll shift position difference upper limit line, and is set to 50 mm in the present embodiment. However, this value changes variously depending on the strip material to be rolled, and is merely exemplified here.

First, during the period from t _{1 to} t ₂ , the upper work roll is 20 mm (FIG. 2B), and the lower work roll is −20 mm (d).
If the feedback control output shown in Fig.
The upper work roll shifts by 20 mm (Fig. C), and the lower work roll shifts by -20 mm (Fig. E). Then, the shift position difference becomes 40mm at t ₂ h (a diagram). t ₂ ~
At t ₃ hours, it is held as it is. next,
In t ₃ ~t ₅ hours, the shift movement control output upper work roll only further 20mm is issued and (b diagram), but the upper work roll starts to shift movement, the upper and lower work roll shift position difference at time t ₄ To reach the upper limit line (a
(Fig.), Further shift movement is held (c).
Figure). It is as it is held in t ₅ ~t ₆ hours. In t ₆ ~t ₇ hours, since the feedback control output for shifting movement of the further 10mm above the work rolls is issued (b view) is, upper and lower work roll shift position difference has already reached the upper limit, the work rolls It is not shifted and remains held. It is as it is held in t ₇ ~t ₈ hours. In t ₈ ~t ₉ hours, when the feedback control output for the shift movement of -10mm to upper work roll is issued (b diagram), the upper work roll the shift position difference is reduced direction (a view) Shift control is performed, and the shift position of the upper work roll is shifted from the 30mm position.
It is shifted to the position of 20 mm (Fig. C).

In the present invention, the edge drop control is performed by controlling the shift movement of the upper and lower work rolls as described above.

[0021]

According to the present invention, defects such as meandering of a strip-shaped material and breakage of a plate, which have been a problem in the past, can be almost eliminated, and operation troubles can be prevented, thereby greatly contributing to stabilization of operation.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram of an edge drop control system of the present invention.

FIG. 2 is a schematic view of a vertical work roll shift rolling stand as viewed from a rolling direction.

FIG. 3 illustrates work roll shift control according to the present invention .
FIG.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B21B 37/00-37/78

Claims (1)

(57) [Claims] 1. A means for axially moving upper and lower work rolls of a rolling mill for rolling a strip material, a work roll shift position detecting means for respectively detecting shift positions of the upper and lower work rolls, and both ends of the strip material Edge drop measuring means for measuring the edge shape of each part, and upper and lower work roll shift change amount calculating means for calculating the respective shift amounts of the upper and lower work rolls from the respective edge drop amounts measured by the edge drop measuring means, A shift position difference upper limit value setting means for setting an upper limit value of the shift position difference between the upper and lower work rolls, and a shift position difference is calculated from the shift positions of the respective work rolls measured by the work roll shift position detecting means. The upper limit value is set by the upper and lower work roll shift position difference upper limit value setting means. When the value exceeds the value, the upper and lower work roll shift position difference calculating means for issuing an alarm signal, and control the respective shift positions of the upper and lower work rolls based on the shift change amount calculated by the upper and lower work roll shift change amount calculating means, An edge drop control device comprising upper and lower work roll shift position control means having a function of canceling a shift change in a direction in which the shift amount increases when the warning signal is received.